Drill



Sept. 27, 1932. G. G. HARRINGTON DRILL 2 Sheets-Sheet Filed July 22. 1936 lNVENTOR M97.

M. Mimi;

ATTORNEY Sept. 27, 1932. G. G. HARRINGTON Filed July 22, 1930 2 Sheets-Sheet 2 q INVE NTOR . J c ATTORNEY Patented Sept. 27 1932 I UNITED STATES PATENT! OFFICE euonen e. HARRINGTON, or HOUSTON, TEXAS, nssreiron T REED nouns. 3171' con:-

PANY, OF HOUSTON, TEXAS,

A CORPORATION or TEXAS DRILL Application filed July 22, 1930. Serial a... 469,666.

This invention relates to deep well drilling apparatus and more particularly to that type of drill embodying removable cutting blades.

Cutting blades of deep well drills are quickly worn by most formations, and they are now removably mounted in the bit head of the drill so that they. maybe replaced. The blade mountings now in use are defective in that they permit movement of the blade in the bit head when the drill is subremoved; and Fig. 4, a fragmentar jected to the usually great drilling strains. Becomingloose, the blades wear the head, out a bore of a diameter other than that predetermined, and are often forced out of the head.

This invention has for its object the provision of a drill embodying removable cutting blades which cannot become loose dur- [ing drilling operations.

.through a central, longitudinal bore 2 for the reception of the conventional core barrel, not shown. In the bottom of the bit head, on opposite sides of its axis, are twin blade slots, each of which opens outwardly and downwardly and has sidewalls 3 and 4 which. converge upwardly and also converge transversely toward the periphery of the head; and an inner wall '5 extending substantially parallel with the longitudinal axis of the head. Each of the side walls 3 hasa depend- I ing bearing extension 6, shown quite clearly by Fig. 4:.

The upper portion of each of the blades 7 is tapered upwardly and also tapered outwardly and has a fiat inner side, so that theblades will fit snugly in the slots with their arenot subjected to any appreciable strains,

their functionbeing merely .to hold the blades inthe slots when the drill is being lowered or elevated in the hole. 4

' Now when the blades are resting upon the bottom of the hole, and the great weight of the drill stem is placedupon them,,they are forced upwardly: into a tight engagement with the walls ofthe slots. The screws 9 do not interfere with the upward movement of the blades because the slots 8 are vertically elongated. And when the drill is actuated in drilling operations, the blades cannot become loose' in the head because the weight of the stem continuously tends to force them tightly into the head, and the engaging walls of the blades and slots positively prevent lateral movement.

Lclaim: v 1. A well-drilling bit blade having an upper portion both tapered toward its upper end and tapered toward itsouter side, and an elongated slot therein.

2.\A rotary core drill bit head having therethrough a central longitudinal bore,

downwardly and outwardly opening slots on opposite sides of its axis, the side walls of "each of said slots converging upwardly and converging outwardly, one of the side walls of each of said slots having a depending hearing extension, the inner wall of each'of said slots extending substantially parallel Wlth" the axis of the head, blades fitting snugly in said slots so that the rear side of each'ofsaid blades bears against one of said extensions,

each of said blades having an axially. elon gated opening therein, and screws carried by the head and extending throughand fitting loosely in said openings.

3. A rotary drill bit head having downwardl and outwardly opening sl0ts on-oppo site si of its axis, the side walls of each of said slots converging'upwardly and converging outwardly, blades fitting snugly in said slots, each of said blades having an axially elongated opening therein, and screws carried 5 by the head and extending through and fit= ting loosely in said openings, said blades be ing gripped by said walls when forced into said slots.

In testimony whereof, I hereunto afiix my 0 signature.

GEORGE G. HARRINGTON. 

